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Jumpering AC

98XJSport

98XJSport

Destiny is the rising sun
Location
Western Maine
Well Im still fighting with my aux. fan not turning on, and Ive read many times that sometimes the fan won't work if your AC isn't pressurized. Well mine hasn't blown cold air in a few years, so I want to test this. Everyone says to jumper, but do I want to jumper the high or low pressure switch? Where is said switch, and what wires am I jumpering, if anyone knows?

Thanks.
 
Tow something heavy up a hill at a quick pace and on a hot day. Do you have hills in W. ME? Anyway, do something to get it real hot. The fan should come on @ 217*. My a/c doesn't work either, but the new fan came on when I hit traffic after towing the boat for a while. No, I didn't do it just to test the fan; I needed to test the boat.
 
Long story short yes. Ive overheated it several times. Fan NEVER turns on. All the wiring is intact and correct. Fan works when 12V is applied. But it won't turn on when the temps are up, or the AC is on. Bottom line I havn't been able to get the PCM to send the fan relay a ground signal, and Im out of things to try...
 
Seems like you could just jump the fan straight to the battery, no? It's just a motor with blades on it. Shold be ok long enough to see if the fan will turn.
 
1. jump the fan straight to the battery. unplug the fan, get 2 lenghts of wire, one from the fan to the positive battery terminal, the other to a ground. doesn't matter which, if you get it wrong, the fan runs backwards

2. there is an eletrical connection on the side of your a/c compressor. unplug it. if thats unplugged the a/c will not come on, but your fan controller will think the a/c pressure is fine. you now have a manually controlled fan that you can turn on by turning your HVAC to A/C.
 
98XJSport said:
...Fan works when 12V is applied...
Click to expand...
Similar issues here. I ended up wiring a switch and relay and isolating it (the fan) completely from the PCM. I think my issues are with the AC system as well. The clutch will not always engage and the cold air is only temporary.

Its a PITA, but for now I'm not over-heating while I wait for enough time to address the HVAC/cooling issues thoroughly.
 
law.74 said:
Similar issues here. I ended up wiring a switch and relay and isolating it (the fan) completely from the PCM. I think my issues are with the AC system as well. The clutch will not always engage and the cold air is only temporary.

Its a PITA, but for now I'm not over-heating while I wait for enough time to address the HVAC/cooling issues thoroughly.
Click to expand...

Exactly! Like I said, I have tested the whole electrical system from the PCM plug out, it all works. Even cleaned the grounds, the PCM just never tells it to turn on. I have it wired into a relay and switch, but I would like to regain the safety of having the computer turn it on as well.

I will give unplugging all connectors to the compressor a try...
 
If this is for a 98, your switch should look like this, I think. This is a shot of my 97, from the passenger side.

Image088.jpg


Sorry for the crappy cell pic, but that's all I've got atm. Anywho, you can see the trigger wire for the compressor as well (with the green wire tapped into it, which tells my fan controller to kick my main elec fan on). The PS has two wires going into it, and is mounted directly to the line, and the trigger for the clutch is a single wire, and runs into the back of the compressor. You should be able to tell which is which easily.
 
That little thing is the pressure switch? No wonder I couldn't find it, I was looking for something more complex. Thanks for the pics!
 
I still got nothing, I unplugged that plug and jumpered the 2 wires. Nothing changed.
 
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